Răspuns :
[tex](a + 7) \times 5 = 60 \\ 5 \times a + 5 \times 7= 60 \\ 5 \times a = 60 - 35 \\ 5 \times a = 25 \\ a = 25 \div 5 \\ a = 5 \\ verificare \\ (5 + 7) \times 5 = 60 \\ 12 \times 5 = 60 \\ 60 = 60 \: (adevarat)[/tex]
[tex](a + 7) \times 5 = 60 \\ 5 \times a + 5 \times 7= 60 \\ 5 \times a = 60 - 35 \\ 5 \times a = 25 \\ a = 25 \div 5 \\ a = 5 \\ verificare \\ (5 + 7) \times 5 = 60 \\ 12 \times 5 = 60 \\ 60 = 60 \: (adevarat)[/tex]